1. Field of the Invention
This invention relates to a bipolar, water-activated battery, and specifically, to an improved bipolar battery that is water-activated, that is low cost in construction, allowing for robotic construction, and that includes an improved bipolar cell structure that can be replicated with a plurality of adjacent cells forming the bipolar battery, the cells being compressed together using a novel, sealable frame structure for each cell.
2. Description of the Prior Art
The use of primary reserve, water-activated batteries is well known. A water-activated battery has a long shelf life and finds service in a single application that, once activated by salt or fresh water, operates for a period of time, whereafter its usefulness is spent. When a water-activated primary reserve battery is used in a system such as a sonobuoy, which is an acoustic receiver and RF transmitter disposed into the ocean for anti-submarine warfare exercises, once activated, the battery energy is expended, and the sonobuoy's usefulness terminates. Therefore, thousands of sonobuoys a year are typically used.
Bipolar batteries are well known. With the use of a bipolar electrode, once face acts as the anode surface, and the opposite face acts as a cathode surface when an electric current is passed through a cell. Each cell need not be directly electrically connected with wires in series. With the use of a plurality of bipolar cells which are stacked adjacent each other, each cell will act in series with the other cells, forming the total voltage output of the battery, dependent on the number of cells disposed side-by-side.
It is desirous to use cuprous iodide and magnesium as the electrode elements for a water-activated battery. These electrode elements have been used in primary reserve water-activated batteries. One of the drawbacks of the primary reserve battery is the amount of manual labor required in building up a plurality of primary reserve cells and electrically connecting them together in the water-activated battery, using cuprous iodide and magnesium.
The present invention overcomes the problems of cost of construction and greatly improves the ease of manufacture by providing a bipolar battery cell frame that is elastomeric, and that acts also as a gasket for each cell. The invention utilizes a special alloy foil wall to separate each cell that is bipolar and which does not interact chemically with either the cuprous iodide or magnesium so that the individual cell structure is preserved. Using the present frame and structure, a plurality of cells are stacked together under compression due to the elastomeric frame which seals each cell from each other to prevent electrolyte transfer between cells. Through the use of the present elastomeric frame and overall construction with the special alloy foil wall that separates each cell, a bipolar compression cell is disclosed that, when stacked upon each other, forms a bipolar, water-activated battery that can be constructed at low cost.